There are some roles that come along just in the nick of time to rescue a career. Such was the case when Quentin Tarantino offered the role of "Nice Guy" Eddie in Reservoir Dogs (1992) to Chris Penn, who has been found dead at 40.

At the time Penn was living in the shadow of his older brother Sean, had become addicted to cocaine, been arrested for bar brawls and had played supporting roles in three movie stinkers, Return From the River Kwai (1989), Mobsters and Future Kick (both 1991).

Given the fanatical following Reservoir Dogs attracted, it was inevitable that Penn would gain cult status with its appearance. Eddie is one of the film's more colourful characters, a mix of loving son and cold-hearted killer, loyal friend and betrayer, calm "problem fixer" and uncontrollable thug. Fans still debate the question of who shot Eddie.

In an interview some years ago, Penn said: "Nobody shot him. It was a mistake. Harvey Keitel was supposed to shoot Lawrence Tierney (who played Penn's gang boss father), then shoot me, then get squibbed. But what happened was the squib (a small explosive charge resembling a bullet hit) on Harvey went right off after he shot Lawrence, so he went down, but my squib went off anyway, so I went down. Quentin said, 'You know what? It'll be the biggest controversy of the film. We're leaving it in'."

At the time of his death, 6ft-tall Penn weighed 310lbs, though his early film roles show that he was not always plump. Francis Ford Coppola gave him one of his first parts as a member of Matt Dillon's street gang in Rumble Fish (1983). This was followed by All the Right Moves (also 1983), in which, as the jovial pal of high-school football star Tom Cruise, he spoils his chances of a college football career by getting his cheerleader girlfriend pregnant.

A few years later, in real life, Penn had a daughter who died. "She was only two days old, she was born premature and her lungs were just too weak," he said. "I went kind of overboard. I just used it as an excuse to do as many drugs as I could. It took me a year or so to figure out what I was doing, and by then I was completely addicted."

Nevertheless, he was steadily building a promising career: as Kevin Bacon's friend in Footloose (1984), as an anarchic college kid in A Wild Life (1984); as a nasty young villain in Clint Eastwood's Pale Rider (1985); and, playing opposite Sean and their mother, Eileen Ryan, in the gripping family drama At Close Range (1985).

After Reservoir Dogs, Penn's best roles came in the Tarantino-scripted True Romance (1993), as a malicious cop who, when asked by a wounded crook to call an ambulance, replies, "Shut up. I'll call you a hearse"; as a swimming pool cleaner who listens with mounting anger to his wife performing phone sex in Robert Altman's Short Cuts (1993); and as an unhinged gangster in Abel Ferrara's The Funeral (1996).

His latest film (he had completed two others) was the comedy The Darwin Awards, which had its premiere at the Sundance festival last week. His co-star Winona Ryder recalled him talking about the inequalities of Hollywood pay scales. "He said, 'I'm just grateful for the work'," Ryder remembered. "I thought he would be cynical like me, but he had this immense gratitude."

Penn is survived by his elder brothers, Sean and Michael, and his mother.